1. Field of the Invention
The present invention relates to Chinese herbal medicine extracts. In particular, the present invention relates to a use of the crude extracts or extracts of Plectranthus Amboinicus (Lour.) Spreng (PA) for treating rheumatoid arthritis (RA).
2. Description of the Prior Art
As a result of the use of various palliative medicaments and immunosuppressive agents, the treatment of rheumatoid arthritis has made great progress. Most studies reveal that when palliative medicaments or immunosuppressive agents are used as soon as the early outbreak, the destruction rate of bones can be effectively reduced. At present, the medicaments for treating rheumatoid arthritis are classified into the following three groups:
1. Non-steroidal anti-inflammatory drugs (NSAIDs), for example, aspirin, indomethacin, or naproxen, which can effectively inhibit inflammation and alleviate pain effect.
2. Anti-rheumatic drugs (ARDs), referred to as disease modifying anti-rheumatic drugs (DMARDs), for example, gold preparation, hydroxychloroquine, methotrexate (MTX) or penicillamine, which can inhibit conditions and improve immune abnormalities.
3. Steroids, referred to as corticosteroids, which are anti-inflammatory, and can be used as immunosuppressive agents.
Additionally, clinically common palliative drugs include sulfasalazine, and immunosuppressive agents include cyclosporine, azathioprine, or cyclophosphamide. Furthermore, since some antibiotics, such as minocycline, can inhibit enzymes, inhibit bone absorption, and inhibit production of inflammatory substances, they can be used for treating rheumatoid arthritis as well. Many treatment models have been proposed for the use of medicaments and treatment timing, such as Sawtooth therapy, Step-down bridge therapy, staging therapy, and target therapy. The spirit of these treatment models undoubtedly is to use various palliative medicaments or immunosuppressive agents alone or in combination in the early stages.
However, the shortcoming of these medicaments is that side effects will be caused as they work, especially steroids. Frequently, anti-inflammatory medicaments cause abnormalities in the bowel tract, e.g., bleeding, and the like.
A protein antagonist, such as TNF-α, could be also used clinically to palliate conditions rapidly, but it needs to be used in an invasive mode, which is inconvenient. Additionally, as the herb Radix Tripterygii Wilfordii has anti-inflammatory, bactericidal, and fever and pain relief effects, it is currently used for treating rheumatoid arthritis; however, security considerations may be taken due to its toxic side effect.
According to statistics, 1% of the population suffers from rheumatoid arthritis across the world. Accordingly, it is of great importance to develop convenient, safe, and efficient medicaments for treating rheumatoid arthritis.
Plectranthus Amboinicus (Lour.) Spreng (PA) originates in Malaysia and India, and is frequently planted by average families as an ornamental herb. The common herb PA is the epigeal portion of the Plectranthus Amboinicus (Lour.) Spreng plant, the aliases of which are Lysimachia capillipes Hemsl, Spearmint, Patchouly, Indian peppermint, or pogostemon cablin. East Indians use this as a cloth-perfuming agent, and the English found PA's charming scent after they introduced shawl cloth from India in 1820. If the leaves of PA were placed into the clothes directly, not only did the clothes acquire a scent, but also, the clothes were prevented from being moth-eaten. The PA is considered as having bactericidal, exciting, or insect repelling functions in Southeast Asia. Also, PA can cure bites from vipers or mosquitoes and insects, and also can relieve headaches, flatulence, vomiting, diarrhea, and fever, and the like. Plectranthus Amboinicus (Lour.) Spreng essential oil is the most popular flavor in Asia. In aromatherapy, PA is used to facilitate epithelial cell regeneration, and the treatments of acne, eczema, Hong Kong foot, and dry cracking of skin. Even more, PA is an excellent anti-depressant and aphrodisiac that functions to relieve anxiety and enhance libido.
In the present invention, it is unexpectedly found that crude extracts or extracts of PA have the efficacy of treating RA.